Prusa slicer - Multiple Extruders, Infill extruder setting  

RE: Prusa slicer - Multiple Extruders, Infill extruder setting

There is a hierarchy of the different ways you can set a filament/color. The settings in the Multiple Extruders page are basically at the bottom of that hierarchy so it only comes into play if you've left the model's extruder set to Default in the Plater view. Painting the model with the painter tool is at the top of the hierarchy so it overrides all other settings including the Multiple Extruders page.

By default, Tool Painter colors go all the way to the centeroid of the model, so you probably won't see the infill setting come into play even if you've left the extruder to Default as previously mentioned. One way to use both would be setting a "Maximum width of a segmented region" depth to limit how deep into the model the Painter Tool color penetrates from the model surface; any infill past that set depth will then use the infill setting.

If you're only talking about weird 'vertical depth color changes' from the use of the Painter Tool then there isn't really a simple setting to directly affect 'painted vertical depth' at the moment. But there are workarounds like setting more 'top solid layers' until you can't see the infill. You can also use modifier shapes to affect extruder/color settings, but that's something where you have to annoyingly place shapes into an opaque object, so the more complex your model the more difficult it is to do this. Optimally, you'd color-seperate your model's parts during your CAD workflow, so you can simply set extruder/color in the model list in the Plater view and not have to mess with the automated parts of the Painter Tool.